EP1656098A1

EP1656098A1 - Concentrated oil-in-water emulsions

Info

Publication number: EP1656098A1
Application number: EP04757412A
Authority: EP
Inventors: George Endel Deckner
Original assignee: Procter and Gamble Co
Current assignee: Procter and Gamble Co
Priority date: 2003-08-07
Filing date: 2004-08-02
Publication date: 2006-05-17
Also published as: JP2007501786A; CN1832721A; MXPA06001476A; JP4276265B2; US20050031568A1; WO2005016293A1

Abstract

In a first aspect, the invention concerns oil-in-water emulsions having a concentrated oil phase wherein at least about 50 % by weight of the emulsion is disontinous oil phase, and comprising water-soluble polymeric emulsifiers having a molecular weight of at least 500 Daltons. In a second aspect, products, such as cosmetic products, are provided, comprising the emulsions.

Description

CONCENTRATED OIL-IN-WATER EMULSIONS

FIELD

The present application concerns oil-in-water emulsions having a concentrated internal phase and products, such as cosmetic products, comprising the emulsions.

BACKGROUND

Emulsions are generally stabilised by appropriate emulsifying surfactants, which, by virtue of their amphiphillic structure, reside at the oil/water interface and thus stabilise the dispersed droplets. These surfactants typically exhibit the disadvantage, however, of penetrating and potentially irritating the skin, eyes and scalp and generally giving poor skin feel. Furthermore, the use of conventional surfactants to manufacture emulsions typically necessitates the application of heat during processing, which can also be disadvantageous, in that it can restrict the ability to include heat-sensitive ingredients and in that it may also limit the types of place in which the manufacturing method may be performed - safety and other concerns, may, for example, prohibit manufacturing the emulsions in certain desired locations.

Another disadvantage of traditional surfactants is that they may cause materials to re-emulsify after the emulsion breaks - emulsion breakage allows delivery of emulsified materials, but re- emulsification, such as after application of a personal cleansing composition to the skin during washing/showering, may reduce the desired benefit (because emulsified emollients and actives are washed off the skin in this example).

A further disadvantage of conventional surfactants is their inability to satisfactorily emulsify polar oils, such as oils having a high solubility parameter.

Concentrated emulsions having a high discontinuous phase, wherein the discontinuous phase comprises water or oil, for example, are known and have found application in a number of technologies, such as fuels, cosmetics and foods - an everyday example of these emulsions is mayonnaise (which may typically comprise about 70% vegetable oil in water). These concentrated emulsions have also found application in the cosmetic area because the concentrates can stably contain high concentrations of, for example, emollients, moisturisers and sunscreens, which can then be diluted down using simple cold mixing to obtain the desired end product. Reference may be made to US 4,606,913 and US 5,976,604, which teach concentrated emulsions.

In the light of the above considerations, it would be beneficial to develop oil-in-water emulsions which have a reduced capacity to irritate human skin and membranes and provide improved skin feel. In addition, it would be advantageous to develop emulsions, which are more substantive to the substrate to which they are applied, such as human skin or fabrics, and exhibit a reduced tendency to re-emulsify once broken.

SUMMARY

According to a first aspect of the invention, an emulsion is provided comprising at least 50% by weight of the emulsion of discontinuous oil phase, an aqueous continuous phase and emulsifier, wherein at least 70% by weight of the total weight of emulsifier consists of one or more water- soluble emulsification polymers, the or each water-soluble emulsification polymer having a molecular weight of at least 500 Daltons, a 0.1 %wt aqueous solution of the or each water-soluble emulsification polymer having a surface tension of 15-60 mN/m (15-60 dynes/cm) when measured at 25°C.

As used herein, the term "oil-in-water" or "o/w" means that an oil phase is dispersed in an aqueous phase, such that the aqueous phase is the continuous phase and the oil phase the discontinuous phase.

According to a second aspect of the invention, personal care, health care and laundry products are provided comprising from 0.01 to 30%wt, preferably from 0.25 to 5%wt of the emulsion according to the first aspect of the invention.

DETAILED DESCRIPTION

All weights, measurements and concentrations herein are measured at 25°C on the composition in its entirety, unless otherwise specified.

Unless otherwise indicated, all percentages of compositions referred to herein are weight percentages of the total composition (i.e. the sum of all components present) and all ratios are weight ratios. Unless otherwise indicated, all polymer molecular weights are weight average molecular weights.

Unless otherwise indicated, the content of all literature sources referred to within this text are incorporated herein in full by reference.

Except where specific examples of actual measured values are presented, numerical values referred to herein should be considered to be qualified by the word "about".

The present invention relates to emulsions having a concentrated internal or discontinuous oil phase, which represents at least 50% by weight of the emulsion, preferably at least 70%, more preferably at least 80% and more preferably still from 80 to 93% by weight of the emulsion.

The oil phase according to the invention may comprise any water immiscible material that is liquid at ambient conditions; any material that is solid at ambient conditions, has a melting temperature of less than 100°C and melts to form a water immiscible liquid; mixtures of such materials.

As used herein in relation to the oil phase, the term "water immiscible" includes materials having a Hildebrand Solubility Parameter of around 5-12 calories/cc (209 - 502 kJ/m²). The solubility parameter is defined as the sum of all attractive forces radiating out of a molecule. The total Nan der Waals force is called the Hildebrand Solubility Parameter and can be calculated using Hildebrand's equation using boiling point and MW data. Methods and a computer program for calculating the Hildebrand Solubility Parameter are disclosed by CD. Naughan in J. Cosmet. Chem. 36, 319-333 (September/October 1985).

Materials comprised within the oil phase may have any polarity and may include aliphatic or aromatic hydrocarbons, esters, alcohols, ethers, carbonates, fluorocarbons, silicones, fluorosilicones or derivatives thereof.

Solid materials that may be present in the oil phase include waxes. As used herein, the term "wax" includes natural and synthetic waxes. The class of natural waxes includes animal waxes, such as beeswax, lanolin, shellac wax and Chinese insect wax; vegetable waxes, such as carnauba, candelilla, bayberry and sugar cane; mineral waxes, such as ceresin and ozokerite; petrochemical waxes, such as microcrystalline wax and petrolatum. The class of synthetic waxes includes ethylenic polymers and polyol ether-esters, chlorinated naphthalenes and Fischer-Tropsch waxes. For more details, please refer to see Rδmpp Chemie Lexikon, Georg Thieme Nerlag, Stuttgart, 9^th Edition, 1995 under "Wachse".

Advantageously, materials comprised within the oil phase, including the melted waxes, have a viscosity in the range from 0.005 to 30,000cm²/s (0.5 to 3,000,000 cst), preferably from 0.005 to 20,000cm²/s (0.5 to 2,000,000 cst), more preferably from 0.005 to 3500cm²/s (0.5 to 350,000 cst).

The aqueous phase of the emulsions according to the invention comprises water and may also comprise additional water-soluble components, such as alcohols; humectants, including polyhydric alcohols (e.g. glycerine and propylene glycol); active agents such as d-panthenol, vitamin B₃ and its derivatives (such as niacinamide) and botanical extracts; thickeners and preservatives.

Advantageously, the emulsions according to the invention comprise substantially no electrolyte. As used herein, the term "electrolyte" includes substances that form ions in aqueous solution and the term "substantially no electrolyte" means that an emulsion according to the invention comprises less than 0.001% electrolyte by weight of the emulsion. It is beneficial to exclude electrolytes because the diluted emulsions may become much more difficult to thicken when they are present - many thickeners are highly sensitive to salt levels. Thickeners are frequently used in emulsions to increase the viscosity of the water phase, thereby reducing the ability of oil phase droplets, which typically have a lower density than the aqueous phase, to rise to the top of an emulsion formulation (so-called "creaming").

Preferably, the viscosity of the aqueous phase does not exceed 2 kg/ms (2000 cps), measured using a Brookfield Digital Rheometer Model DN-III, with an RN2 spindle at 20rpm (Brookfield Engineering Laboratories- Stoughton Ma.) at 20°C. Above this point, emulsification may become extremely difficult, especially when the internal oil phase is present at high levels, such as 80- 90% by weight of the emulsion.

The water-soluble emulsification polymers according to the invention have a molecular weight of at least 500 Daltons, since below this level, the resulting emulsions have poor skin feel. Skin feel improves with increasing molecular weight and it is preferred that the water-soluble emulsification polymers according to the invention have a molecular weight above 3000 Daltons, more preferably above 9000 Daltons and more preferably still, above 10,000 Daltons. At the levels of emulsifier present in the emulsions according to the invention, the molecular weight of the water-soluble emulsification polymers advantageously does not exceed 130 kiloDaltons; above this point, the viscosity of the aqueous phase may reach a level that hinders emulsification, especially when the internal oil phase is present at levels of 80-90% by weight of the emulsion.

At least 70%, preferably at least 85%, more preferably at least 95% and more preferably still 100% by weight of the total weight of emulsifier consists of one or more water-soluble emulsification polymers.

Surprisingly, it has been found that any water-soluble polymer fulfilling the defined molecular weight and surface tension criteria may be used to emulsify the emulsions according to the present invention - this applies regardless of the chemical nature of the water-soluble polymer, so that polymers of widely differing chemistries may be employed. Non-limiting water-soluble polymers which may be employed according to the invention include: alkylated polyvinylpyrrolidone, such as buylated polyvinylpyrrolidone commercialised as "Ganex P904" by ISP Corp.; terephthalate polyesters, including polypropylene glycol terephthalate, such as the product commercialised as "Aristoflex PEA" by Clariant A.G.; mono alkyl esters of poly(methyl vinyl ether/maleic acid) sodium salt, including mono butyl ester of poly(methyl vinyl maleic acid sodium salt) such as included in the product commercialised as "EZ Sperse" by ISP Corp; isobutylene/ethylmaleimide/hydroxyethyl copolymer, such as included in the product commercialised as "Aquafix FX64" by ISP Corp.; (3-dimethylaminopropyl)-methacrylamide/3- methacryloylamidopropyl-lauryl-dimthyl-ammonium chloride, such as included in the product commercialised as Styleze W20 by ISP Corp.; ρeg-12 dimethicone, such as the product commercialised as "DC 193" by Dow Corning Corp.

Advantageously, at least one of the non-alkoxylated, water-soluble polymers according to the invention has film-forming properties. These properties are found in higher molecular weight polymers, especially those having a molecular weight above 10,000 Daltons. The film-forming property may further increase the substantivity of the emulsions on the substrate versus traditional surfactants, including alkoxylated surfactants. Dried-down oil-in-water emulsions comprising traditional surfactants, including alkoxylated surfactants, suffer from the disadvantage that they may re-emulsify when wetted, whereas the present non-alkoxylated, water-soluble polymers are less liable to do that. Without wishing to be bound by theory, it is believed that the substantivity of the present compositions may be further increased if the polymers exhibit film-forming properties, because the film-forming polymer may form a film over the oil phase to retain it on the substrate. Of the commercially available polymers listed above, Ganex P904, EZ Sperse, Aquafix FX64 and Styleze W20 are all film-forming polymers.

The emulsions according to the invention may comprise from 0.1% to 15%, preferably from 0.1% to 5% and more preferably 0.1 to 2.5% by weight water-soluble emulsification polymer.

The emulsions according to the invention may be manufactured in the following way:

A typical emulsion might contain 1-5% water-soluble emulsification polymer and 6-15% aqueous phase, the aqueous phase comprising 100% water or a mixture of water and other water-soluble components. In a first step, the water-soluble emulsification polymer is added to the aqueous phase with mixing. Following this, discrete batches of 2-3% of the total weight of oil are titrated sequentially into the aqueous phase accompanied by gentle mixing to obtain a uniform consistency prior to addition of the following batch. This is continued until around 20% of the total weight of oil has been added. At this point the remainder of the oil may be added more rapidly and in a continuous fashion with more vigorous mixing until a uniform emulsion comprising all the oil is obtained. Mixing is continued until a uniform consistency is obtained exhibiting a typical particle in a desired range. A typical particle size would be in the range from 1 to 20 microns. The concentrated emulsion obtained typically comprises above 70%, and more often from 80 to 93% internal oil phase by weight of the emulsion.

The emulsions according to the invention may be employed as products in their own right. Makeup remover gels, for example, may comprise the present concentrated emulsion. In addition, however, the present emulsions may be incorporated into other products as components thereof. According to a second aspect of the invention, products are provided comprising the emulsions according to the first aspect of the invention. Examples of such products include personal care products, such as lotions for hand and body, shampoo compositions, make-up, perfume and perfume gel compositions and lotions for baby wipes; laundry products such as fabric softener and liquid laundry detergent; health care products, such as vapour rub creams; coatings for tissue towels.

Personal care, health care and laundry products may comprise from 0.01 to 30%wt, preferably from 0.25 to 12%wt, more preferably 0.25 to 5%wt of the above-defined concentrated emulsions. Non-limiting examples of materials that may be included in such products are thickeners; surfactants, such as non-ionic, anionic, cationic, zwitterionic and amphoteric surfactants; humectants, such as polyhydric alcohols, including glycerine and propylene glycol; pigments, including organic and inorganic pigments; preservatives; chelating agents, antimicrobials, perfumes.

Measurement Methods

Testing the solubility of the water-soluble emulsification polymers

As used herein in relation to the emulsification polymers, the term "water-soluble" includes polymers fulfilling the following condition: a l%wt solution of the polymer in de-ionised water at room temperature gives at least 90% transmittance of light having a wavelength in the range from 455 to 800nm. Testing was carried out by passing the polymer solution through a standard syringe filter into a 1cm path length cuvette having a pore size of 450 nm and scanning using an HP 8453 Spectrophotometer arranged to scan and record across 390 to 800 nm. Filtration was carried out to remove insoluble components.

Measurement of surface tension

The method used for measuring surface tension of fluid is the so-called "Wilhelmy Plate Method". The Wilhelmy plate method is a universal method especially suited to establishing surface tension over time intervals. In essence, a vertical plate of known perimeter is attached to a balance, and the force due to wetting is measured. More specifically:

A 0.1 %wt aqueous solution of water-soluble emulsification polymer is made up in de-ionised water. The polymer solution is then poured into a clean and dry glass vessel, the solution temperature being controlled at 25°C. The clean and annealed Wilhelmy Plate is lowered to the surface of the liquid. Once the plate has reached the surface the force which is needed to remove the plate out of the liquid is measured.

The equipment used and corresponding settings are as follows: Device: Kriiss Tensiometer K12, manufactured by Kriiss GmbH, Borsteler Chausee 85-99a , 22453 Hamburg- Germany (see www.kruess.com).

Plate Dimensions: Width: 19.9mm; Thickness: 0.2mm; Height: 10mm

Measurement Settings: immersion depth 2mm, Surface Detection Sensitivity O.Olg, Surface Detection Speed 6mm/min, Values 10, Acquisition linear, Maximum Measurement Time 60sec

The plate is immersed in the fluid and the corresponding value of surface tension is read on the display of the device. Instructions can be found in the user manual edited by „Kriiss GmbH Hamburg 1996" Version 2.1.

Examples

The following examples further describe and demonstrate the preferred embodiments within the scope of the present invention. The examples are given solely for the purpose of illustration, and are not to be construed as limitations of the present invention since many variations thereof are possible without departing from its scope.

Example 1; Hand and Body Lotion

'Dow Corning 1503 fluid is a dimethicone and dimethiconol produced by Dow Corning ²EZ Sperse is a 25% solution of mono butyl ester of poly(methyl vinyl maleic acid sodium salt) and is a copolymer of maleic anhydride and methyl vinyl ether reacted with water/butanol to form a half ester, which is neutralised with sodium hydroxide. EZ Sperse is produced by ISP Corp. Procedure to make a lOOQg batch of concentrated oil-in-water emulsion

Isohexadecane, isopropyl isostearate and DL-tocopheryl acetate were mixed using a Kitchen Aid Ultra Power Mixer until uniform. The water and EZ Sperse were mixed in the same way. The isohexadecane/isopropyl isostearate/DL-tocopheryl acetate were then added to the water/EZ Sperse at a rate of 8g/minute while continually mixing with a Kitchen Aid Ultra Power Mixer having a paddle attachment at a setting of "4". Following complete addition, the Dow Corning 1503 was added to the mixture at the same rate and mixed in the same way until a uniform mixture was obtained.

³Phenoxyethanol and Methyl-, Ethyl-, Buyl-, Popyl and Isobutylparaben from Nipa Labs Inc. ⁴Seppigel 305 is polyacrylamide & C13-14 isoparaffin & laureth-7 and is available from Seppic Group. ⁵System 3 AM500 is a mixture of water, petrolatum, lecithin, hydrogenated lecithin, and polyphosphorylcholine glycol acrylate commercialised by Collaborative Laboratories Inc. ⁶System 3 AM900 is a mixture of water, cetearyl alcohol, hydrogenated polyisobutene, lecithin, hydrogenated lecithin, butylene glycol and polyphosphorylcholine glycol acrylate commercialised by Collaborative Laboratories Inc.

Procedure to make a lOOQg batch of hand and body lotion All mixing was carried out using a Kitchen Aid Ultra Power Mixer with a paddle attachment and a speed setting of "2".

The de-ionised water, glycerine, Phenonip and d-panthenol were mixed until uniform at which point the Sepigel 305 was dispersed into the mixture and also mixed until uniform. Following this, the System 3 AM900 was added to the mixture and mixed until uniform, the System 3 AM500 was added and mixed until uniform and finally the concentrated oil-in-water emulsion was added to the mixture and mixed in to create a hand and body lotion of uniform consistency.

Example 2: Make-up foundation

'Kobo Products Inc., titanium dioxide and isopropyl titanium triisostearate ²Kobo Products Inc., hydrated ferric oxide and isopropyl titanium triisostearate ³Kobo Products Inc., ferric oxide and isopropyl titanium triisostearate ⁴Kobo Products Inc., iron oxide and isopropyl titanium triisostearate ⁵Butylated polyvinylpyrollidone obtained from ISP Corp., Inc.

Procedure to make pigment pre-mix

The Ganex P904 and water were mixed using a Kitchen Aid Ultra Power Mixer until uniform. The pigments were then added to the Ganex P904/water and mixed using a Cito Unguator mixer for 1 minute at a setting of 5.

Concentrated Oil-In-Water Emulsion Material %wt Weight (g)

⁶Cyclohexsiloxane fluid produced by Dow Coming ⁷Cyclopentasiloxane fluid produced by Dow Coming

Procedure to make a lOOQg batch of concentrated oil-in-water emulsion

Tridecyl neopentanoate, Dow Coming 245 and 246 were mixed using a Kitchen Aid Ultra Power Mixer until uniform. The water and EZ Sperse were mixed in the same way. The Tridecyl neopentanoate/Dow Coming 245 and 246 were then added to water/EZ Sperse at a rate of 8g/minute while continually mixing with a Kitchen Aid Ultra Power Mixer having a paddle attachment at a setting of "4".

⁸Aluminium starch octylsuccinate and boron nitride obtainable from National Starch & Chemical

Procedure to make make-up foundation All mixing was carried out using a Kitchen Aid Ultra Power Mixer with a paddle attachment and a speed setting of "2".

The Phenonip was dispersed in the water and mixed. The Dry Flo Elite BN was dispersed in the glycerine and mixed until uniform, then the glycerine/Dry Flow Elite BN was added to the Phenonip/water and mixed until uniform. The Seppigel 305 was added to the mixture and mixed until smooth and lump free. At this point, the pigment was mixed in and mixing was continued until the colour was uniform. Lastly, the concentrated oil-in-water emulsion was mixed in until uniform to create the finished make-up foundation.

Example 3: shampoo formulation

¹ Dimethicone of molecular weight 330,000 from General Electric Corp.

Procedure to make a batch of oil-in-water emulsion

The Aristoflex PEA and 5% water were mixed using a Kitchen Aid Ultra Power Mixer until uniform. The CF330M was then added at a rate of 8g/minute while continually mixing with a Kitchen Aid Ultra Power Mixer having a paddle attachment at a setting of "4". Due to the high viscosity, the emulsion was then diluted with the remainder of the water while continually mixing with a Kitchen Aid Ultra Power Mixer having a paddle attachment at a setting of "4".

Procedure to make shampoo

About one-third to all of the total alkyl sulfate surfactant (ammonium laureth-3 sulfate (added as a 26% solution) and/or ammonium lauryl sulfate (added as a 25% solution)) is added to a jacketed mix tank and heated to about 74°C with slow agitation to form a surfactant solution. Cocamide MEA and fatty alcohol are added to the tank and allowed to disperse. Ethylene glycol distearate (EGDS) is then added to the mixing vessel, and melted. After the EGDS is well dispersed (usually about 5 to 20 minutes) the preservative is added and mixed into the surfactant solution. This mixture is passed through a heat exchanger where it is cooled to about 35°C and collected in a finishing tank. As a result of this cooling step, the ethylene glycol distearate crystallizes to form a crystalline network in the product. The remainder of the ammonium laureth sulfate, lauryl sulfate and other ingredients including the concentrated oil-in-water emulsion are added to the finishing tank with ample agitation to insure a homogeneous mixture.

Example 4: perfume gel

Procedure to make the concentrated oil-in-water emulsion The EZ Sperse and 7.5%wt water were mixed using a Kitchen Aid Ultra Power Mixer until uniform. The fragrance oil was then added at a rate of 8g/minute while continually mixing with a Kitchen Aid Ultra Power Mixer having a paddle attachment at a setting of "4". Due to the high viscosity, the emulsion was then diluted with the remainder of the water while continually mixing with a Kitchen Aid Ultra Power Mixer having a paddle attachment at a setting of "4".

Procedure to make perfume gel

All mixing was carried out using a Kitchen Aid Ultra Power Mixer with a paddle attachment and a speed setting of "2".

The Seppigel 305 was dispersed in the water and mixed until a smooth gel was obtained, at which point the perfume o/w emulsion was added and mixed until a uniform consistency perfume gel was produced.

Example 5: make-up remover gel

All mixing was carried out using a Kitchen Aid Ultra Power Mixer with a paddle attachment and a speed setting of "2". The Ganex P904 was dissolved in the de-ionised water with mixing. Isohexadecane was added into the Ganex P904/water at a rate of 8g/minute and mixed until uniform. Lastly, the glycerine was added to the mixture and the concentrated emulsion was again mixed to create a transfer- resistant make-up remover gel.

Example 6: baby wipe lotion

'Peg- 12 dimethicone from Dow Coming

Procedure to make oil-in-water emulsion

The DC 193 and deionised water were mixed using a Kitchen Aid Ultra Power Mixer until uniform. The DC 1503 was then added to the DC193/water at a rate of 8g/minute while continually mixing with a Kitchen Aid Ultra Power Mixer having a paddle attachment at a setting of "4" until a uniform mixture was obtained.

Αcrylates/vinyl isodecanoate crosspolymer ² DMDM Hydantoin and iodoproponyl butylcarbamate from Lonza Group Ltd.

Procedure to make baby wipe lotion

The Stabylen-30 was uniformly dispersed into the deionised water using a mixer equipped with a propeller blade, following which the Na₂EDTA and triethanolamine were added to the mixture and mixed in the same way. The Glydant Plus was dissolved into the butylene glycol and remaining water following which the solution was added to the Stabylen/water/Na₂EDTA/triethanolamine. Lastly, the concentrated oil-in-water emulsion was added and the whole was mixed until a baby lotion of uniform consistency was obtained. The baby wipe lotion may be impregnated into any non-woven substrate suitable for use as a baby wipe.

Example 7: Baby Vapour Rub Cream

The essential oils were mixed uniformly, then incorporated into an oil-in-water emulsion having the following composition:

Water and EZ Sperse were mixed using a Kitchen Aid Ultra Power Mixer until uniform. The essential oils were then added to the water/EZ Sperse while continually mixing with a Kitchen Aid Ultra Power Mixer having a paddle attachment at a setting of "4" until a uniform oil-in-water emulsion was obtained.

'Caprylic/Capric Triglyceride (and) Sodium Acrylates Copolymer from BASF ²Laureth-4 from Uniquema

All mixing was carried out using a Kitchen Aid Ultra Power Mixer.

The following premixes were prepared:

A. Glycerine and water B. 1,2-hexanediol, ethyl paraben and benzyl alcohol C. Luvigel EM and Brij 30

Following preparation of the premixes, premix A was added to premix B with mixing until uniform. After this, premix C was added and mixed until a smooth creamy consistency had been achieved, at which point the AM 900 was incorporated, again with mixing. Finally, the concentrated oil-in-water emulsion was added and the whole was mixed to achieve a uniform consistency baby vapour rub cream.

Example 8; Topical Analgesic Composition

The pre-mix components are thoroughly mixed using a Kitchen Aid Ultra Power Mixer until all the menthol has dissolved.

Water and EZ Sperse were mixed using a Kitchen Aid Ultra Power Mixer until uniform. The analgesic active pre-mix was then added to the water/EZ Sperse while continually mixing with a Kitchen Aid Ultra Power Mixer having a paddle attachment at a setting of "4" until a uniform oil- in-water emulsion was obtained.

All mixing was carried out using a Kitchen Aid Ultra Power Mixer. The following premixes were prepared:

Following preparation of the premixes, premix A was added to premix B with mixing until uniform. After this, premix C was added and mixed until a smooth creamy consistency had been achieved, at which point the AM 900 was incorporated, again with mixing. Finally, the concentrated oil-in-water emulsion was added and the whole was mixed to achieve a uniform consistency topical analgesic active cream.

Example 9: Anti-Acne Gel

¹ PPG- 15 Stearyl Ether from Uniquema.

The pre-mix components were heated to 50°C and thoroughly mixed using a propeller mixer until the salicylic acid had dissolved to leave a clear solution.

Water and Ganex P904 were mixed using a Kitchen Aid Ultra Power Mixer until uniform. The anti-acne active pre-mix was then added to the water/Ganex P904 while continually mixing with a Kitchen Aid Ultra Power Mixer having a paddle attachment at a setting of "4" until a uniform oil-in-water emulsion was obtained.

²Seppigel 305 is polyacrylamide & C13-14 isoparaffϊn & laureth-7 and is available from Seppic Group.

All mixing was carried out using a Kitchen Aid Ultra Power Mixer.

The Seppigel 305 was added to the water and mixed until a viscous uniform dispersion was obtained. The concentrated oil-in-water emulsion was then added to the Seppigel 305/water and mixed until a uniform consistency anti-acne gel was obtained.

Example 10: wax emulsion

Procedure to make oil-in-water emulsion

The EZSperse, water and glycerine are mixed until uniform. This mixture was heated to 70°C. Separately, the petrolatum was also heated to 70°C. The petrolatum was then slowly added to the aqueous phase and continuously mixed with a Kitchen Aid Mixer equipped with a paddle blade. Mixing was continued until a uniform consistency was obtained. It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to one skilled in the art without departing from the scope of the present invention.

Claims

WHAT IS CLAIMED IS:

1. Emulsion comprising (a) at least about 50% by weight of the emulsion of discontinuous oil phase; (b) an aqueous continuous phase; and (c) emulsifier; wherein about 70% to about 100% by weight of the total weight of emulsifier consists of one or more water-soluble emulsification polymers; wherein the or each water-soluble emulsification polymer has a molecular weight of at least about 500 Daltons; wherein a 0.1 %wt aqueous solution of the or each water-soluble emulsification polymer has a surface tension of about 15 to about 60 mN/m (about 15 to about 60 dynes/cm) when measured at about 25°C.

2. The emulsion of claim 1, wherein at least about 85% by weight of the total weight of emulsifier consists of one or more water-soluble emulsification polymers.

3. The emulsion of claim 1, wherein about 100% by weight of the total weight of emulsifier consists of one or more water-soluble emulsification polymers.

4. The emulsion of claim 1 comprising greater than about 70%wt of the oil phase.

5. The emulsion of claim 1 comprising from about 80 to about 93%wt of the oil phase.

6. The emulsion of claim 1 , wherein the or each oil comprised within the oil phase has a Hildebrand Solubility Parameter of about 5 to about 12 calories/cc (about 209 to about 502 kJoule/m²).

7. The emulsion of claim 1, wherein the or each oil comprised within the oil phase has a viscosity from about 0.005cm²/s to about 30,000cm²/s.

8. The emulsion of claim 1, wherein the or each water-soluble emulsification polymer has a molecular weight above about 3000 Daltons.

9. The emulsion of claim 1, wherein the or each water-soluble emulsification polymer has a molecular weight above about 10,000 Daltons.

10. Emulsion of claim 1, wherein the or each water-soluble emulsification polymer has a molecular weight of less than about 130 kiloDaltons.

11. The emulsion of claim 1, comprising from about 0.25 to about 7%wt, water-soluble emulsification polymer by weight of the emulsion.

12. The emulsion of claim 1, comprising from 0.25 to 5%wt water-soluble emulsification polymer by weight of the emulsion.

13. The emulsion of claim 1, wherein the emulsifier comprises one or more of the water- soluble emulsification polymers selected from the group consisting of mono alkyl esters of poly(methyl vinyl ether/maleic acid) sodium salt; alkylated polyvinylpyrrolidone; terephthalate polyesters and (3-dimethylaminopropyl)-methacrylamide/3-methacryloylamidopropyl-lauryl- dimthyl-ammonium chloride and mixtures thereof.

14. The emulsion of claim 1 further comprising less than about 0.001% by weight of the emulsion of an electrolyte by weight of the emulsion.

15. A product comprising from about 0.01 to about 30%wt of the emulsion of claim 1, wherein the product is selected from the group consisting of personal care, health care and laundry products.

16. The product of claim 15, comprising from about 0.25 to about 5%wt of the emulsion of claim 1.

17. The product of claim 15, wherein the personal care product is selected from the group consisting of a lotion, a shampoo, a make-up and a perfume gel.

18. The product of claim 17, wherein the lotion is a hand and body lotion.

19. The product of claim 15, wherein the health care product is a vapour rub cream.

20. An emulsion comprising: (a) at least about 50% by weight of the emulsion of discontinuous oil phase; (b) an aqueous continuous phase; and (c) emulsifier; wherein at least about 70% by weight of the total weight of emulsifier consists of one or more water-soluble emulsification polymers; wherein the or each water-soluble emulsification polymer has a molecular weight of at least about 10,000 Daltons; wherein a 0.1 %wt aqueous solution of the or each water-soluble emulsification polymer has a surface tension of about 15 to about 60 mN/m (about 15 to about 60 dynes/cm) when measured at about 25°C; wherein at least one of the one or more water-soluble emulsification polymers is a film-forming polymer.

21. The emulsion of claim 20, wherein all of the water-soluble emulsification polymers are film-forming polymers.

22. An emulsion comprising: (a) at least about 50% by weight of the emulsion of discontinuous oil phase; (b) an aqueous continuous phase; and (c) emulsifier; wherein at least about 70% by weight of the total weight of emulsifier consists of one or more water-soluble emulsification polymers; wherein the or each water-soluble emulsification polymer has a molecular weight of at least about 3000 Daltons; wherein a 0.1 %wt aqueous solution of the or each water-soluble emulsification polymer has a surface tension of about 15 to about 60 mN/m (about 15 to about 60 dynes/cm) when measured at about 25°C; wherein the emulsion comprising less than about 0.001% by weight of the emulsion of electrolyte.

23. An emulsion comprising: (a) at least about 50% by weight of the emulsion of discontinuous oil phase; (b) an aqueous continuous phase; and (c) emulsifier; wherein at least about 70% by weight of the total weight of emulsifier consists of one or more of the water-soluble emulsification polymers selected from the group consisting of mono alkyl esters of poly(methyl vinyl ether/maleic acid) sodium salt; alkylated polyvinylpyrrolidone; terephthalate polyesters and (3 -dimethylaminopropyl)-methacrylamide/3 -methacryloylamidopropyl-laury 1- dimthyl-ammonium chloride.

24. The emulsion of claim 23, wherein about 100% by weight of the total weight of emulsifier consists of one or more of the water-soluble emulsification polymers selected from the group consisting of mono alkyl esters of poly(methyl vinyl ether/maleic acid) sodium salt; alkylated polyvinylpyrrolidone; terephthalate polyesters and (3-dimethylaminopropyl)- methacrylamide/3-methacryloylamidopropyl-lauryl-dimthyl-ammonium chloride.